Files
runc/Vagrantfile.fedora34
T
Kir Kolyshkin e84e7f9376 [1.0] Fix failure with rw bind mount of a ro fuse
As reported in [1], in a case where read-only fuse (sshfs) mount
is used as a volume without specifying ro flag, the kernel fails
to remount it (when adding various flags such as nosuid and nodev),
returning EPERM.

Here's the relevant strace line:

> [pid 333966] mount("/tmp/bats-run-PRVfWc/runc.RbNv8g/bundle/mnt", "/proc/self/fd/7", 0xc0001e9164, MS_NOSUID|MS_NODEV|MS_REMOUNT|MS_BIND|MS_REC, NULL) = -1 EPERM (Operation not permitted)

I was not able to reproduce it with other read-only mounts as the source
(tried tmpfs, read-only bind mount, and an ext2 mount), so somehow this
might be specific to fuse.

The fix is to check whether the source has RDONLY flag, and retry the
remount with this flag added.

A test case (which was kind of hard to write) is added, and it fails
without the fix. Note that rootless user need to be able to ssh to
rootless@localhost in order to sshfs to work -- amend setup scripts
to make it work, and skip the test if the setup is not working.

[1] https://github.com/containers/podman/issues/12205

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
(cherry picked from commit 50105de1d8)

Conflicts:
 - .cirrus.yml: trivial, due to missing commit f0dbefac.
 - .github/workflows/test.yml: due to missing commits 120f74060 and
   3fd1851ce9, resolved manually.
 - Dockerfile: trivial, due to missing commit 24d318b8bb.
 - libcontainer/rootfs_linux.go: due to missing commits 36aefad45d
   and 9c444070ec, resolved manually.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
2021-11-22 10:26:43 -08:00

51 lines
1.6 KiB
Ruby

# -*- mode: ruby -*-
# vi: set ft=ruby :
Vagrant.configure("2") do |config|
# Fedora box is used for testing cgroup v2 support
config.vm.box = "fedora/34-cloud-base"
config.vm.provider :virtualbox do |v|
v.memory = 2048
v.cpus = 2
end
config.vm.provider :libvirt do |v|
v.memory = 2048
v.cpus = 2
end
config.vm.provision "shell", inline: <<-SHELL
set -e -u -o pipefail
# Work around dnf mirror failures by retrying a few times
for i in $(seq 0 2); do
sleep $i
cat << EOF | dnf -y shell && break
config exclude kernel,kernel-core
config install_weak_deps false
update
install iptables gcc make golang-go glibc-static libseccomp-devel bats jq git-core criu fuse-sshfs
ts run
EOF
done
dnf clean all
# Add a user for rootless tests
useradd -u2000 -m -d/home/rootless -s/bin/bash rootless
# Allow root and rootless itself to execute `ssh rootless@localhost` in tests/rootless.sh
ssh-keygen -t ecdsa -N "" -f /root/rootless.key
mkdir -m 0700 -p /home/rootless/.ssh
cp /root/rootless.key /home/rootless/.ssh/id_ecdsa
cat /root/rootless.key.pub >> /home/rootless/.ssh/authorized_keys
chown -R rootless.rootless /home/rootless
# Delegate cgroup v2 controllers to rootless user via --systemd-cgroup
mkdir -p /etc/systemd/system/user@.service.d
cat > /etc/systemd/system/user@.service.d/delegate.conf << EOF
[Service]
# default: Delegate=pids memory
# NOTE: delegation of cpuset requires systemd >= 244 (Fedora >= 32, Ubuntu >= 20.04).
Delegate=yes
EOF
systemctl daemon-reload
SHELL
end